Ug, I completely missed that in the anime, perhaps it was the translation, I saw it fansubbed a while ago (sure, blame the subbers
). Perhaps while you're at it you can explain the following to me? (sorry to go off topic a bit - MAJOR Infinite Ryvius spoiler ahead, don't highlight!)
As for on topic, I suppose these are just little scenes inside of anime, but no, there are no other anime that deal exclusively with incest, except probably some hentai?